PS -> RSS and VSZ Question (vague man page?) 1

[jouell]

When I do a ps aux on Liux , I understand a few things are shown:


RSS:

Resident set size, the non-swapped physical memory that a task has used (in kiloBytes).


and

VSZ:

virtual memory usage of entire process. vm_lib + vm_exe + vm_data + vm_stack


But, Does VSZ also include RSS in its total? Or is it up to the user to add them to see how much memory a process has in use AND swapped?


I know this sounds silly but it seems a little vague to me

Thanks!
-John

 

[Annihilannic]

RSS is a part of VSZ, so you should not add them together.

Annihilannic.

 

[jouell]

Great! Thanks!

Did you get that sense from the man pages or did you have a different source?

Thanks again!
-John

 

[Annihilannic]

I don't recall, from logic probably. VSZ is the virtual memory size of the process, part of which may be in physical memory and part of which may be swapped to disk. RSS is the part which is in physical memory. Perhaps an oversimplification, but that's the way I understand it.

Annihilannic.

 

[jouell]

Makes perfect sense. I tripped up on the "virtual memory" part being distinct and different from "physical memory" in the accounting of ps.


Thanks again for the info!
-John